JPH04266802A - Synergetically bactericidal composition of 2-(decylthio)ethaneamine and 1,2-dibromo- 2,4-dicyanobuthane - Google Patents

Abstract

PURPOSE: To obtain a combination of two types of biocidal materials that give rise to synergistic effects against microorganisms in aqueous systems such that the extent to which the microorganisms are killed exceeds that which one would expect from using the sum of the individual components of the composition. CONSTITUTION: This combination comprises 2-(decylthio)ethaneamine and 1,2- dibromo-2,4-dicyanobutane in amounts effective to inhibit microbial growth. The combination has proven to be particularly effective in inhibiting the growth of Enterobacter aerogenes ATCC 13048 in aqueous systems.

Description

[Detailed description of the invention]

0001

TECHNICAL FIELD This invention relates to the treatment of water systems, and more particularly to the treatment of microorganisms commonly found in industrial water systems such as cooling water systems, air washing water systems, and pulp and paper manufacturing equipment. Concerning a bactericidal substance.

0002

BACKGROUND OF THE INVENTION Slime production by microorganisms is a problem encountered in many industrial water systems. For example, in industrial cooling water systems, the water used is generally tap water;
For large-scale installations, it is often untreated river water. As a result, the water is not sterile, resulting in bacteria building up in the equipment. Furthermore, as the facility water falls along the tower blowers, a large portion of the bacteria is introduced into the air. As a result, it is common for slime-like deposits to form on the surfaces of equipment that come into direct contact with the cooling water. One-time formula (
Both once-through and recirculating refrigeration equipment use large amounts of water as the cooling medium, and slime formation by microorganisms is a widespread and constant problem.

[0003] Slime formation not only causes deterioration of the tower structure in the case of wooden towers, but also tends to clog the equipment and render the equipment inefficient if left to accumulate. Slime transported through the cooling equipment clogs and fouls piping, valves, strainers, etc. Bacteria that are in the water and transported through the water system accumulate on surface sites, such as the surfaces of heat exchangers, forming slime clumps that impede heat exchange and greatly reduce the efficiency of cooling equipment. Slime accumulation also provides an environment conducive to the growth of anaerobic bacteria that thrive in the low oxygen environment beneath the slime. These anaerobic microorganisms can cause pitting and corrosion of metal surfaces.

Slime formed by microorganisms is commonly encountered in paper pulp manufacturing equipment.
Causing equipment contamination, clogging, or corrosion. Slime can also be incorporated into the manufactured paper and cause breakouts on the paper machine, resulting in work stoppages and loss of production time. Slime also causes unsightly staining of the final product, leading to rejection and product waste.

[0005]

The problems discussed above have led to the widespread use of disinfectants in cooling water and pulp and paper manufacturing equipment. A variety of materials have been used in these applications, including chlorine, chlorinated phenols, organobromine, and various organosulfur compounds. Although all of these compounds are generally useful for this purpose, each is associated with various drawbacks. For example, chlorination is limited both by its specific toxicity to slime-forming microorganisms at economical concentrations and by the reactive tendency of chlorine to result in consumption of the chlorine before full biocidal function is achieved. Other disinfectants are associated with odor problems and storage, use, or handling hazards that limit their use. To date, no single compound or class of compounds has achieved clearly established superiority for the applications discussed above.

The use of disinfectants involves continuous or frequent addition to the equipment being treated and requires addition to multiple points or zones within these equipment.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide novel fungicidal compositions that prevent the growth of microorganisms in aqueous systems.

2 which has a synergistic effect on microorganisms in water systems
-(decylthio)ethanamine and 1,2-dibromo-
It is another object of the present invention to provide a fungicidal composition comprising a combination of 2,4-dicyanobutane.

According to the invention, 1,2-dibromo-2,
A fungicidal composition comprising a mixture of 4-dicyanobutane and 2-(decylthio)ethanamine and a method of using the composition is provided, the composition being added to an aqueous system in an amount effective to inhibit the growth of microorganisms. Ru.

[0010] The present invention provides two methods that have a synergistic effect on microorganisms in an aqueous system such that the extent of microbial killing exceeds that expected from the use of the total amounts of the individual components of the composition. It is intended to be used in combination with various bactericidal substances. More particularly, the invention provides 2-(decylthio)ethanamine and 1,2-ethanamine in an amount effective to prevent microbial growth.
A combination comprising dibromo-2,4-dicyanobutane is desired. This combination is effective against Enterobacter aerogenes (Enterobacter aerogenes) in water systems.
aero-genes) ATCC 13048.

2-(decylthio)ethanamine is synthesized by DTEA or XU40 according to US Pat. No. 4,816,061.
Dow Chemical (Dow Ch.
Manufactured by the company ``Emical''. 1,2-dibromo-2,4-dicyanobutane is disclosed in U.S. Patent No. 3,833.
, No. 731, No. 3,873,597, No. 3,877,92
2 and 3,929,858.
Merck Chemical (Merck Chem.
mical) division.

The fungicidal compositions of this invention are generally most effective when added to aqueous systems having a pH above 7, preferably between 8 and 9. The individual germicidal components of the compositions of the invention can be added to the aqueous system separately or premixed and in amounts effective to inhibit microbial growth. 2-(decylthio)ethanamine is generally 0.7
1,2-
Dibromo-2,4-dicyanobutane is generally added in a concentration range of 4.0 to 12.0 ppm. The total concentration of disinfectant in the water system generally ranges from 5 to 14 ppm, and preferably from 5.2 to 13.2 ppm.

The following examples are presented to illustrate the invention in accordance with the principles of the invention and are not intended to limit the invention in any way other than as indicated in the appended claims. Must not be interpreted. All parts and percentages are by weight unless otherwise noted.

[0014]

【Example】

[0015]

[Example 1] 2-(decylthio)ethanamine and 1,
A formulation of 2-dibromo-2,4-dicyanobutane was evaluated for synergism against Enterobacter aerogenes ATCC #13048. The results are as follows.

[0016]

[Table 1] 2-(decylthio)
1,2-dibromo- synergy
Ethanamine
2,4-dicyanobutane index
A1 A2 A
B1 B2 B 0.7
0 2.00 0.35 10.0 20
．． 0 0.50 0.85* 0.70
2.00 0.35 20.0 20.0
1.00 1.35 0.70 2.00
0.35 30.0 20.0 1.5
0 1.85 1.50 2.00 0.
35 60.0 20.0 3.00
3.35 1.50 2.00 0.75
10.0 20.0 0.50 1.2
5 1.50 2.00 0.75 20
．． 0 20.0 1.50 1.75 1
．． 50 2.00 0.75 30.0
20.0 1.50 2.25 1.50
2.00 0.75 60.0 20.0
3.00 3.75 2.00 2.0
0 1.00 10.0 20.0 0.
50 1.50 2.00 2.00 1
．． 00 20.0 20.0 1.00
2.00 2.00 2.00 1.00
30.0 20.0 1.50 2.
50 2.00 2.00 1.00 6
0.0 20.0 3.00 4.00
4.00 2.00 2.00 10.0
20.0 0.50 2.50 4.00
2.00 2.00 20.0 20.
0 1.00 3.00 4.00 2.
00 2.00 30.0 20.0 1
．． 50 3.50 4.00 2.00
2.00 60.0 20.0 3.00
5.00

[0017]

[Example 2]

[0018]

[Table 2] 2-(decylthio) 1
,2-dibromo- synergy
Ethanamine 2
,4-dicyanobutane index
A1 A2 A
B1 B2 B 0.60
2.00 0.30 4.0 30.
0 0.13 IBR 0.60 2.0
0 0.30 8.0 30.0 0
．． 27 IBR 0.60 2.00 0
．． 30 12.0 30.0 0.40
IBR 0.80 2.00 0.40
4.0 30.0 0.13 IB
R 0.80 2.00 0.40
8.0 30.0 0.27 0.67*
0.80 2.00 0.40 12.0
30.0 0.40 0.80* 1.
20 2.00 0.60 4.0
30.0 0.13 0.73* 1.20
2.00 0.60 8.0 30
．． 0 0.13 0.87* 1.20
2.00 0.60 12.0 30.0
0.13 1.00

[0019]

[Explanation of symbols in examples]

[0020]

[Equation 1] Synergy index=A+B In the above formula: A=A1/A2 B=B1/B2 In the above formula: A1=Concentration of 2-(decylthio)ethanamine in the mixture (ppmA1) A2=Concentration of 2-(decylthio)ethanamine in the mixture (ppmA1) MIC end point B
1 = Concentration of 1,2-dibromo-2,4-dicyanobutane in the mixture (ppmA1) B2 = M of 1,2-dibromo-2,4-dicyanobutane
When IC endpoint A+B=1: the combination is additive.

When A+B>1: the combination is antagonistic.

When A+B<1: the combination is synergistic.

Note: * = synergistic IBR = less bacterial reduction MIC = Minimum Inhibitory Concentration (Minimum Inhibitory Concentration)
bitory concentration)

Claims (7)

[Claims] 1. Comprising a synergistic mixture of 2-(decylthio)ethanamine and 1,2-dibromo-2,4-dicyanobutane in an amount effective to inhibit the growth of microorganisms, 2- (decylthio)ethanamine and 1,
2-dibromo-2,4-dicyanobutane is each 0.7-
A microbial killing composition present in a weight ratio of 1.2:4-12. 2. Adding to an aqueous system a composition comprising a mixture of 2-(decylthio)ethanamine and 1,2-dibromo-2,4-dicyanobutane in an amount effective to inhibit the growth of microorganisms. A method for inhibiting the growth of microorganisms in an aqueous system, characterized by: 3. The method of claim 2, wherein the aqueous system is maintained at a pH greater than 7. 4. A method according to claim 2, wherein the aqueous system is maintained at a pH between 8 and 9. 5. 2-(decylthio)ethanamine and 1,2-dibromo-2,4-dicyanobutane each have a content of 0.
3. A method according to claim 2, wherein the weight ratio is 7-1.2:4-12. 6. The method of claim 2, wherein the water system is a cooling water system. 7. The method of claim 2, wherein the aqueous system is a paper pulp production facility.